refactor(#1450): lift shared harness-path resolution into hive-sh4re

hive-sh4re/src/lib.rs

@@ -3,6 +3,7 @@
 use serde::{Deserialize, Serialize};
 
 pub mod assets;
+pub mod paths;
 pub mod priv_proto;
 
 // -----------------------------------------------------------------------------

hive-sh4re/src/paths.rs

@@ -0,0 +1,33 @@
+//! Shared in-container filesystem-path resolution.
+//!
+//! Every process that runs inside an agent container - the harness plus
+//! the out-of-process MCP daemons (bash, matrix, ...) - must resolve the
+//! harness directory layout identically. These helpers previously had to
+//! be hand-mirrored across crates (each copy carrying a "keep in sync"
+//! comment) because there was no shared home for them; they live here so
+//! the resolution exists exactly once.
+
+use std::path::PathBuf;
+
+/// Base harness directory for the current agent. Uses `HYPERHIVE_HARNESS_DIR`
+/// if set (injected by the hive-c0re meta flake after the harness/state
+/// split); falls back to a `harness/` sibling of `HYPERHIVE_STATE_DIR` for
+/// pre-split / dev deployments.
+#[must_use]
+pub fn harness_dir() -> PathBuf {
+    if let Some(p) = std::env::var_os("HYPERHIVE_HARNESS_DIR") {
+        return PathBuf::from(p);
+    }
+    let state = std::env::var("HYPERHIVE_STATE_DIR").unwrap_or_default();
+    let state_path = PathBuf::from(&state);
+    state_path
+        .parent()
+        .map_or_else(|| PathBuf::from(state), |p| p.join("harness"))
+}
+
+/// Directory where out-of-process MCP daemons write loose-end summary
+/// files (`<name>.json`) for the harness to scan in `get_loose_ends`.
+#[must_use]
+pub fn mcp_loose_ends_dir() -> PathBuf {
+    harness_dir().join("mcp-loose-ends")
+}